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It depends on whether the light is within a medium or just in vacuum. Afaik light in vacuum behaves entirely linear (so waves of different frequencies don't interact). But there are materials where light does indeed interact with light of different frequencies. One effect like this is so-called four-wave mixing.
In general you can take a look at non linear optics
I will! Thank you! Also, it's super fun that there's exceptions based on the medium; I had no idea. I was picturing air or vacuum when I conceived of the original question, so now I have other things to look into!
I second the other poster’s suggestion to look into nonlinear optics. A really common application is frequency doubling, also known as second harmonic generation, which doubles the energy of the photons. So an 800 nm laser (red) can be converted to 400 nm (green) with this method.
The National Ignition Facility (NIF) actually uses frequency tripling of the laser pulses right before they enter the target chamber. That’s pretty wild, I had intended to look up NIF to give a high profile example of second harmonic generation, I hadn’t realized they were actually doing third harmonics.
Another optics-based phenomenon that I think maybe strays too far from the intent of your initial question, but is too cool not to share, is laser Wakefield acceleration. A very high power laser pulse will push electrons out of its path in plasma or materials via the ponderomotive force. This charge separation creates electric field gradients on the order of billions of volts per centimeter, which can accelerate electrons or other charged particles to relativistic energies. So you can start with a green laser pulse and wind up producing gamma-ray beams, either by slamming the electrons into a stopping material or by Compton scattering other low energy photons off the relativistic electrons.
I really appreciate the extra info! It's fascinating.
I'm recently an ex-fundie, so learning about all the cool stuff happening in science is like finding out your childhood house has a million secret rooms you never knew about.